Electrocatalyst for biomass conversion and plastic degradation and preparation method and application thereof

Abstract

This invention discloses an electrocatalyst for biomass conversion and plastic degradation, its preparation method, and its application. The catalyst uses a carbon-based material as a catalyst support, supporting multi-component metals and multi-component metal oxides to form a binary metal interface structure, denoted as NM / TMO. x The catalyst is NM / TMO / C, wherein NM is one or more of the noble metals Au, Ag, Ir, In, Pd, Pt, Ru, and Rh, and TM is one or more of the transition metals Co, Cu, Mn, Ni, Fe, and Ti, wherein the loading of NM is 0.5wt%–35wt% and the loading of TM is 1wt%–30wt%. The preparation and application methods of this catalyst are also provided. The catalyst NM / TMO / C of this invention exhibits high reaction rates, high selectivity for multi-electron products, good CO resistance, good stability, and strong reproducibility at low potentials in the electrocatalytic oxidation of biomass and plastic degradation.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis technology for biomass conversion and plastic degradation, and particularly relates to an electrocatalyst for biomass conversion and plastic degradation, its preparation method and application. Background Technology

[0002] Biomass is an important energy source, and the selective catalytic oxidation of biomass-based alcohols and aldehydes is one of the most important reactions in organic synthesis, with wide applications in the production of fine chemicals. One of the key pathways for converting carbohydrates into various organic acids and furans is the catalytic oxidation of alcohols and aldehydes. However, due to the complexity of the reaction system and the multiple reaction pathways, its catalytic mechanism is not yet clearly understood. For example, 5-hydroxymethylfurfural (HMF), as an important biomass platform chemical, is widely available in nature. HMF can be directly generated from the dehydration of glucose or fructose. Because it possesses both alcoholic hydroxyl and aldehyde groups, it is considered an ideal model for studying the liquid-phase selective oxidation catalytic mechanism of alcohols and aldehydes (selective activation of carbon-oxygen single and double bonds). However, currently, the selective catalytic oxidation of biomass-based alcohols and aldehydes mainly adopts thermocatalysis, which inevitably requires high temperature and pressure, precious metal catalysts, and some toxic oxidants, which is inconsistent with the principles of modern green synthesis. In contrast, electrocatalytic alcohol / aldehyde oxidation offers mild and controllable operating conditions (ambient temperature and pressure), continuous reaction capability, and low cost, making it a promising alternative method for the production of fine chemicals. The selective electrocatalytic oxidation of 5-hydroxymethylfurfural (5-HMF) can replace the traditional anodic oxygen evolution reaction (OER) and reduce the cell voltage. Simultaneously, it can selectively generate high-value-added products such as 2,5-furandicarboxaldehyde (DFF), 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), 5-formyl-2-furancarboxylic acid (FFCA), and 2,5-furandicarboxylic acid (FDCA), making it a "two birds with one stone" reaction. A review of numerous literature and patents reveals that current research on the high-potential oxidation of HMF to FDCA (>1 V) is extensive, primarily focusing on transition metal Co-based and Ni-based catalysts. However, the reaction generating the 6-electron product (FDCA) typically requires a higher voltage than the 2-electron product (HMFCA) and the 4-electron product (FFCA). In this regard, researchers have adjusted and optimized nickel hydroxide by introducing noble metals such as Pt and Pd, but the required voltage remains very high (>1.35 V). For example, in the literature: Wang Shuangyin et al. "Platinum-modulated redox properties of Ni(OH)2 and adsorption kinetics of 5-hydroxymethylfurfural", Angewandte Chemie 2021(60), a nickel hydroxide-supported Pt nanoparticle catalyst was designed and synthesized by hydrothermal and high-temperature reduction with ethylene glycol. As a three-dimensional electrocatalyst with high FDCA selectivity at high potential (1.40 V), Pt itself cannot be used as an active species because it is oxidized, but it improves the electrocatalytic activity of nickel hydroxide for HMF.Ru's regulation of NiO has also been reported, such as Tsinghua University, Duan Haohong, et al. "Selective electro-oxidation of biomass-derived alcohols to aldehydes in neutral media: promoting water dissociation on nickel oxide-supported ruthenium single-atom catalyst", Angewandte Chemie 2022(61). This study uses hydrothermal generation of nickel hydroxide followed by calcination to nickel oxide, and then impregnation and calcination to prepare Ru1 / NiO catalysts. The Ru single atom itself does not act as an active species but only provides *OH species, promoting the selective oxidation of HMF by the NiO catalyst under neutral conditions at a high potential (1.30 V). In addition, the catalytic performance of some transition metal oxides has also attracted much attention. Nanjing Forestry University, Chen Zupeng et al. "Self-reconstructed surface sulfate-modified copper oxide nanorods for efficient and stable electro-oxidation of 5-hydroxymethylfurfural", Nano Letters 2023, prepared a copper sulfide nanosheet (Cu2S NSs) model as a "pre-catalyst". A series of structural and compositional analyses confirmed that in electrochemical HMFOR, S in Cu2S NSs... 2- Anions in the form of SO4 2- The form of exudation and covalent bonding is present in the self-reconstructed copper oxide nanorods (CuO-SO4). 2- NRs) surface. CuO-SO4 2- NRs, acting as a "real catalyst," achieved complete conversion of 5-hydroxymethylfurfural over fifteen consecutive cycles, with a yield and Faradaic efficiency of over 99.9% for the target product 2,5-furandicarboxylic acid (FDCA), and no deactivation. However, catalysts capable of achieving 100% FDCA selectivity at low potentials have not yet been reported.

[0003] Furthermore, plastics, especially PET plastics, are one of the main culprits of "white pollution." Common household items such as mineral water bottles, plastic cans, and the casings of some appliances are primarily made of PET plastic, whose main component is polyethylene terephthalate (PET). This polymer is difficult to degrade under natural conditions for hundreds of years. Currently, the world consumes and produces 245 million tons of plastic annually, and the current methods for treating PET plastic waste include landfill, incineration, and recycling. While landfill and incineration are simple to operate, the resulting waste gas and wastewater cause secondary pollution to the environment. Therefore, recycling is a more recommended method. However, due to the high economic cost of plastic recycling and the low performance of recycled plastics, the current recycling rate is low. The main recycling method currently involves physical crushing and catalytic degradation through heating. This not only requires a catalyst to react under high temperature and pressure conditions, but also makes automated continuous degradation difficult due to the difficulty in collecting the products. In contrast, electrocatalytic degradation of plastics offers milder conditions, allows for the control of products through potential regulation, and enables automated continuous production. PET's polyester structure allows it to be easily hydrolyzed in alkaline electrolytes into terephthalic acid and ethylene glycol. Ethylene glycol can undergo highly selective electrooxidation to generate formate. This process holds promise for coupling with electrocatalytic oxidative cracking to produce high-value-added chemicals from PET. Therefore, research on the electrocatalytic upgrading and recycling of waste PET plastics has broad prospects. For example, Tsinghua University, Duan Haohong, et al. "Electrocatalytic upgrading and recycling of polyethylene terephthalate to prepare chemical products and H2 fuel", Nature Communications 2021(12), used non-precious metal cobalt nickel phosphide as a bifunctional electrocatalyst to upgrade and recycle waste polyethylene terephthalate (PET) plastics. The electrocatalytic conversion of waste PET plastics into high-value-added terephthalic acid (PTA), potassium diformate (KDF) and H2 fuel. However, this technology requires a relatively high potential (~1.36 V vs. RHE) to oxidize and dehydrogenate to form active intermediates Ni(OH)O and Co(OH)O, which determines that the electrocatalyst can only react at high potentials and cannot achieve electrocatalytic conversion at low potentials.

[0004] A deep understanding of catalyst structure and its relationship to the selectivity of C=C, CO, and C=O bond activation is a crucial step towards the universal design of highly efficient catalysts for ultra-low potential biomass conversion and plastic degradation. Achieving high selectivity for six-electron products (FDCA) at low potentials on noble metal-based materials enables efficient HER (hydrogenation-enhanced ion exchange) and the production of high-value-added organic products at ultra-low input voltages (<1 V). More importantly, it provides a new solution for the rational design of low-cost, low-voltage, and stable electrolyzers for converting intermittent electricity generated from renewable energy sources.

[0005] Therefore, based on the above problems, developing a catalyst and catalytic method for the electrocatalytic selective oxidation of biomass conversion and plastic degradation that has a high reaction rate, good stability, low cost, energy saving and environmental protection is of great practical significance. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electrocatalyst and catalytic method for the electrocatalytic oxidation of biomass conversion and plastic degradation that has a high catalytic oxidation reaction rate at low potential (<1.0 V), high selectivity of corresponding multi-electron products, good CO antitoxicity, good stability, and strong reproducibility.

[0007] The technical problem solved by this invention is achieved through the following technical solution: A catalyst for the electrocatalytic selective oxidation of biomass conversion and plastic degradation, wherein the catalyst uses a carbon-based material as a catalyst support and supports multi-component metals and multi-component metal oxides to form a binary metal interface structure, denoted as NM / TMO. x / C, where NM is one or more of the noble metals Au, Ag, Ir, In, Pd, Pt, Ru, and Rh, and TM is one or more of the transition metals Co, Cu, Mn, Ni, Fe, and Ti, wherein the NM loading is 0.5wt%-35wt% and the TM loading is 1wt%-30wt%. The metal loading is obtained by measuring the content of transition metals or heavy metals in the catalyst by ICP-MS.

[0008] A method for preparing a catalyst for the electrocatalytic selective oxidation of biomass conversion and plastic degradation includes the following steps: (1) Take a transition metal salt solution and add ultrapure water, stir, and then add the catalyst support and stir; (2) Add a reducing agent to the solution obtained in step (1) and perform mechanical stirring reaction; (3) The sample TM / C with transition metal loaded on a carrier was obtained by filtration, washing, centrifugation and drying; (4) Take the TM / C sample obtained in step (3) and disperse it in one or two noble metal precursor solutions, and stir continuously. Then filter, wash, centrifuge and dry to obtain catalyst NM / TM / C. (5) Take the NM / TM / C obtained in step (4) and put it into a muffle furnace. Calcinate it in air. After calcination, cool it to room temperature to obtain NM / TMO. x / C.

[0009] Further, the transition metal mentioned in step (1) is one or more of Co, Cu, Mn, Ni, and Fe.

[0010] Further, the catalyst support described in step (1) is activated carbon, carbon black, graphene and its derivatives, carbon quantum dots, carbon nanofibers or carbon nanotubes.

[0011] Further, the reducing agent in step (2) is sodium borohydride solution, potassium borohydride solution, hydrazine hydrate or hydrogen peroxide.

[0012] Furthermore, the noble metal precursor solution in step (4) is Au-containing... 3+ Ag + Ir 4+ In 3+ Pd 2+ Pt 4+ Ru 3+ ,Rh 3+ One or more of the following in aqueous solution.

[0013] Furthermore, in steps (3) and (4), the water used for washing needs to be deoxygenated by argon gas beforehand.

[0014] Furthermore, in step (5), the roasting temperature in the muffle furnace is 100~200°C, and the roasting time is 2~3 h.

[0015] The catalyst for the electrocatalytic oxidation of biomass conversion and plastic degradation prepared by the above method can be applied to the electrocatalytic oxidation of biomass or plastics; in particular, the catalyst can be applied to the low-potential (<1 V) oxidation of organics such as benzyl alcohol, ethylene glycol, 5-hydroxymethylfurfural, glycerol, and PET plastics.

[0016] Specifically, the method for electrocatalytic oxidation of biomass or plastics using the above-mentioned catalyst is as follows: First, 0.3 M PET plastic was hydrolyzed in 2 M KOH at 60℃ for 18 hours to obtain a PET hydrolysate solution. This solution was then prepared into a 1 mol / L KOH + 1.0 mol / L PET plastic hydrolysate solution (terephthalic acid and ethylene glycol monomers), and transferred to a three-electrode system (H-type electrolytic cell, both cathodes are 1 mol / L KOH solution). For biomass conversion, different substrates were used; for example, in the selective electrooxidation of HMF to prepare FDCA, the electrolyte was 1 mol / L KOH + 50 mmol / L HMF, using carbon paper (1 cm²). 2 A platinum foil electrode was used as the working electrode, a mercury / mercury oxide electrode (Hg / HgO) as the reference electrode, and 300 μL of catalyst ink (5 mg / mL, 0.25% Nafion) was dropped onto the surface of the working electrode. Both biomass conversion and plastic electrooxidation were performed at room temperature using an electrochemical workstation (BioLogic EC-Lab).

[0017] The innovation of the present invention compared with the existing technical solutions lies in: This invention prepares metal oxides loaded on carbon black surfaces via precipitation. Then, a weakly acidic aqueous solution of a noble metal precursor (pH < 7) is added and stirred to etch the metal oxides. The etching of the metal oxides causes an increase in the pH of the solution, leading to the directional precipitation of the noble metals on the oxide surface. This process prepares noble metal oxides loaded on an ultrathin oxide surface. Subsequently, the noble metals are reduced in situ using a cyclic voltammetric electrochemical method to form a sufficient quantity of noble metal / transition metal oxides (NM / TMO). x The interface effectively promotes efficient electrocatalytic oxidation of biomass conversion and plastic degradation at room temperature. Unlike existing technologies that use hydrothermal methods with reducing agents to prepare noble metal / transition metal oxides, this invention first prepares the metal oxide, loads it onto the carbon black surface, then directionally precipitates and performs in-situ electrochemical reduction. This allows for precise loading of noble metals at room temperature without the need for a reducing agent. Furthermore, the resulting transition metal oxides are significantly smaller (ultra-thin) than the nanoparticles prepared by traditional hydrothermal methods. Loading noble metals onto ultra-thin transition metal oxides allows for the formation of a sufficient amount of noble metal / transition metal hydroxide (NM / TMO). x This is a crucial prerequisite for the interface, which traditional methods cannot achieve. Thanks to this structure, which differs from traditional catalysts, the NM / TMO designed in this invention... x For example, Pt / CuO x The catalyst achieved 100% selectivity for FDCA in the HMF electrocatalytic reaction at a low voltage (0.6 V), which is the highest selectivity reported to date at low potentials. Furthermore, it underwent five consecutive electrochemical cycles, demonstrating good catalyst stability and selectivity. This invention utilizes the construction of NM / TMO... x The binary metal interface structure significantly improves the electrocatalytic oxidation performance of the catalyst for biomass conversion and plastic degradation at low potentials (<1.0 V).

[0018] This invention has the following advantages and positive effects: (1) The multi-metal interface structure nanocatalyst NM / TMO in this invention x It can efficiently electrocatalyze the oxidation of biomass and plastics at room temperature, and improve the selectivity of multi-electron products. For example, this catalyst can achieve near 100% selective oxidation of HMF to FDCA at low voltage (0.6V).

[0019] (2) This invention constructs NM / TMO xThe / C binary metal interface structure significantly improves the electrocatalytic oxidation performance of the catalyst for biomass conversion and plastic degradation at low potentials (<1.0 V). For example, at a low potential of 0.75 V, the HMF oxidation current can reach more than 22.5 mA, enabling high-current and efficient electrocatalytic oxidation of biomass conversion and plastic degradation processes. Attached Figure Description

[0020] Figure 1 Pt / CuO of Embodiment 1 of the present invention x High-resolution transmission electron microscopy image of a bimetallic catalyst.

[0021] Figure 2 The catalyst in Example 2 of this invention was subjected to HMF oxidation CV test at room temperature using cyclic voltammetry.

[0022] Figure 3 The charge-time curve of the catalyst in Example 3 of this invention is obtained by electro-oxidation of HMF using the potentiostatic method at 0.75 V vs. RHE.

[0023] Figure 4 The product distribution results were obtained by sampling and testing the electrolyte after the HMF electrocatalytic oxidation reaction of the catalyst in Example 3 of the present invention at different voltages (0.3 V, 0.4 V, 0.5 V, 0.6 V, 0.75 V, 0.9 V).

[0024] Figure 5 The product distribution results are obtained from 12 consecutive cycle stability tests of HMF with the catalyst of Example 3 of the present invention at a voltage of 0.75 V vs. RHE.

[0025] Figure 6 The catalyst in Example 9 of this invention was tested for HMF oxidation LSV at room temperature using cyclic voltammetry.

[0026] Figure 7 The product distribution results were obtained by sampling and testing the electrolyte after the HMF electrocatalytic oxidation reaction of the catalyst in Example 9 of the present invention at different voltages (0.6 V, 0.8 V, 1.0 V).

[0027] Figure 8 The product distribution results are obtained from 10 consecutive cycle stability tests of Pt / TiO2 on the catalyst of Example 9 of the present invention at a voltage of 0.8 V vs. RHE. Detailed Implementation

[0028] First, it should be noted that the specific structure, features, and advantages of the present invention will be illustrated by examples below. However, all descriptions are for illustrative purposes only and should not be construed as limiting the present invention in any way. Furthermore, any single technical feature described or implied in the embodiments mentioned herein can still be arbitrarily combined or deleted among these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0031] Example 1 Preparation of CuO / C and Pt / CuO x Pt / CuO x -Etching catalyst.

[0032] Preparation method of CuO / C: Weigh 0.054 g CuCl·2H2O (100% purity, theoretical 10wt%) and add 90 ml of ultrapure water into a flask, sonicate for 30 min and stir for 30 min. Add 0.18 g carbon black, sonicate for 30 min, and stir for 2 h. Weigh 0.25 g NaBH4 37.83 g / mol and dissolve in 10 mL of ultrapure water, add to the solution, and stir for 6 h after the addition is complete. Finally, filter and wash with water that has been pre-purified with Ar to obtain Cu / C; Pt / CuO x Preparation method: Cu / C was added to 100 mL of ultrapure water (previously deoxygenated by Ar). While stirring, chloroplatinic acid hexahydrate (g / 10 mL, 0.836 mL was added directly using a pipette) was added dropwise, followed by stirring for 12 h. The mixture was filtered, dried overnight at 60°C, and labeled as "Pt / Cu / C". PtCu / C was then placed in a muffle furnace and calcined in air at 150°C for 2 h at a heating rate of 5°C / min. -1 After calcination, the mixture was cooled to room temperature to obtain Pt / CuO. x catalyst.

[0033] Pt / CuO x -Etching preparation method: 20 mg of Pt / CuO x The catalyst was diluted in 30 mL of aqueous solution, etched with 2 M dilute nitric acid (2.66 mL) for 12 h, and then filtered and dried.

[0034] Figure 1 This is a transmission electron microscope (TEM) image of the Pt / CuOx bimetallic catalyst. Example 2 Electrocatalytic oxidation of HMF was carried out using the catalyst prepared in Example 1 and commercial Pt / C.

[0035] Pt / CuO x As a catalyst: a 1 mol / L KOH solution was prepared as the cathode electrolyte (20 mL), and a 1 mol / L KOH + 50 mmol / L HMF solution was prepared as the anolyte (20 mL). These solutions were then transferred to a three-electrode system (H-type electrolytic cell) using carbon paper (1 cm²). 2 A platinum foil electrode was used as the working electrode, a mercury / mercury oxide electrode (Hg / HgO) as the counter electrode, and a mercury / mercury oxide electrode as the reference electrode. 300 μL of catalyst ink (5 mg / mL, 0.25% Nafion) was dropped onto the working electrode surface. Both biomass conversion and plastic electrooxidation were performed at room temperature using an electrochemical workstation (BioLogic EC-Lab). The reaction results are as follows: Figure 2 As shown.

[0036] Pt / CuO x -Etching as a catalyst: The operation steps are the same as those for Pt / CuO above. x As a catalyst, Pt / CuO x Replace with Pt / CuO x -Etching, reaction results are as follows Figure 2 As shown.

[0037] CuO / C as catalyst: The operation steps are the same as those for Pt / CuO above. x As a catalyst, Pt / CuO x The reaction results after replacing CuO / C are shown in the attached figure. Figure 2 As shown.

[0038] Commercial Pt / C as catalyst: The operation steps are the same as those for Pt / CuO described above. x As a catalyst, Pt / CuO x Replacing with commercial Pt / C at a scan rate of 5 mV / s, the reaction results are as follows: Figure 2 As shown.

[0039] from Figure 2 As can be seen, CuO / C did not exhibit any reactivity in the electrocatalytic oxidation of HMF, while Pt / CuO... x The bimetallic catalyst achieved a peak current density of 22.5 mA / cm². 2 It is a commercial Pt / C catalyst (3.5 mA / cm). 2 6.4 times that of the single-metal catalyst (Pt / CuO) after etching away CuO. More importantly, x The catalytic performance was significantly reduced by etching, with the peak current density dropping to 9.8 mA / cm². 2 This is because the Cu-O-Pt interface is crucial for the electrocatalytic oxidation of HMF, indicating that the noble metal / transition metal hydroxide NM / TMO... x The interface effectively promotes efficient electrocatalytic oxidation of biomass conversion and plastic degradation at room temperature.

[0040] Example 3 Pt / CuO x Pt / CuO x -Etching, voltage constant product testing of commercial Pt / C catalysts.

[0041] The reaction conditions were as follows: a 1 mol / L KOH solution was prepared as the cathode electrolyte (20 mL), and a 1 mol / L KOH + 5 mmol / L HMF solution was prepared as the anolyte (10 mL). These solutions were then transferred to a three-electrode system (H-type electrolytic cell) using carbon paper (1 cm²). 2 A platinum foil was used as the working electrode, a mercury / mercury oxide electrode (Hg / HgO) as the counter electrode, and a mercury / mercury oxide electrode as the reference electrode. 300 μL of catalyst ink (5 mg / mL, 0.25% Nafion) was dropped onto the working electrode surface. The reaction was tested using an electrochemical workstation (BioLogic EC-Lab) at a constant voltage of 0.75 V (vs. RHE) at room temperature. The reaction results are as follows: Figure 3 As shown.

[0042] Example 4 In Example 3, the electrolyte after HMF electrocatalytic oxidation reaction using the catalyst at different voltages (0.5 V, 0.6 V, 0.75 V, 0.9 V) was sampled and the product distribution was detected.

[0043] The product testing conditions are as follows: The reaction was carried out at different voltages (0.5 V, 0.6 V, 0.75 V, 0.9 V) and at different coulombic values ​​(0 C, 9.65 C, 19.3 C, 29.95 C), with a sample size of 50 μL. Each sample was diluted to 1 mL with 950 μL of 5 mM ammonium formate aqueous solution (70%) + methanol (30%). The product was quantitatively detected using high-performance liquid chromatography (HPLC). After the column pressure stabilized, detection was performed using a full-wavelength UV detector with a diode array. The wavelength with the strongest product response and highest resolution (265 nm) was selected for spectral collection and quantification. Each injection volume was 10 μL. The product data were converted to standard values ​​and statistically analyzed.

[0044] Pt / CuO x Pt / CuO x -Etching, product test results of commercial Pt / C catalysts at different voltages are as follows: Figure 4 .

[0045] from Figure 4 As can be seen, the products of the reactions of different catalysts at different voltages (0.5 V, 0.6 V, 0.75 V, 0.9 V) differ significantly, with Pt / CuO showing the most significant difference. x The selectivity for FDCA at 0.75 V is close to 100%, compared to Pt / CuO after etching. x - The etching (66.3% FDCA selectivity) and commercial Pt / C (37.1% FDCA selectivity) catalysts showed significant improvements. A literature review and comparison revealed that Pt / CuO... x The bimetallic catalyst exhibits the highest FDCA product selectivity at low potentials (<1.0 V) that has not been reported before.

[0046] Example 5 For Pt / CuO x Perform cycle stability testing and product detection The stability test and product detection conditions were as follows: 1 mol / L KOH solution was prepared as the cathode electrolyte (20 mL), and 1 mol / L KOH + 5 mmol / L HMF solution was prepared as the anolyte (10 mL). These solutions were then transferred to a two-electrode system (flow electrolytic cell) and coated with Pt / CuO. x Carbon paper of catalyst (4 cm) 2A carbon paper coated with a commercial Pt / C catalyst was used as the cathode, with 3 mL of catalyst ink (10 mg / mL, 0.25% Nafion) dropped onto the working electrode surface. Chronoamperometry was performed at 0.75 V (vs. RHE) at room temperature using an electrochemical workstation (BioLogic EC-Lab). The reaction solution was pumped across the electrode surface, and 50 μL samples were collected at regular intervals. These samples were diluted to 1 mL with 950 μL of 5 mM ammonium formate aqueous solution (70%) + methanol (30%). Quantitative analysis of the product was performed using high-performance liquid chromatography (HPLC). After column pressure stabilization, detection was performed using a full-wavelength UV detector with a diode array. The wavelength with the strongest product response and highest resolution (265 nm) was selected for spectral collection and quantification, with each injection volume being 10 μL. Product data from multiple long-term reactions were recorded, and standard conversions and statistical analyses were performed.

[0047] from Figure 5 As can be seen from this, Pt / CuO x The products of the catalytic oxidation reaction carried out by the catalyst at a voltage of 0.75 V showed little difference, and the selectivity for FDCA was very high, approaching 100%, indicating that the Pt / CuO catalyst... x The catalyst exhibits good stability and high reproducibility.

[0048] Example 6 Preparation of Pd / CuO x catalyst: Preparation method of CuO / C: Weigh 0.054 g CuCl·2H2O (100% purity, theoretical 10 wt%) and add 90 ml of ultrapure water into a flask, sonicate for 30 min and stir for 30 min. Add 0.18 g carbon black, sonicate for 30 min, and stir for 2 h. Weigh 0.25 g NaBH4 37.83 g / mol and dissolve in 10 mL of ultrapure water, add to the solution, and stir for 6 h after the addition is complete. Finally, filter and wash with water that has been pre-purified with Ar to obtain Cu / C.

[0049] Pd / CuO x Preparation method: Pd / CuO x -Etching preparation method: Take 0.035 g of the above Pd / CuO x The solution was placed in a beaker, and 30 mL of 0.5 mol / L dilute nitric acid solution was added. The mixture was mechanically stirred at room temperature for 2.0 hours to remove CuO. After filtration and washing, the mixture was washed several times with ethanol and deionized water. The mixture was then placed in a vacuum drying oven at 60℃ for 24 hours, ground, and weighed to obtain the etched Pt / CuO. x -Etching.

[0050] Example 7 The catalyst prepared in Example 6 was used to conduct experiments on the electrocatalytic oxidative degradation of plastics.

[0051] First, 0.3 M PET plastic was hydrolyzed in 2 M KOH at 60℃ for 18 hours to obtain a PET hydrolysate solution. This solution was then prepared into a 1 mol / L KOH + 1.0 mol / L PET hydrolysate solution (terephthalic acid and ethylene glycol monomers), and transferred to a three-electrode system (H-type electrolytic cell, both cathodes were 1 mol / L KOH solution). The electrolyte was 1 mol / L KOH + 50 mmol / L HMF. Carbon paper (1 cm²) was used for electrolysis. 2 A platinum foil electrode was used as the working electrode, a mercury / mercury oxide electrode (Hg / HgO) as the reference electrode, and 300 μL of catalyst ink (5 mg / mL, 0.25% Nafion) was dropped onto the surface of the working electrode. Biomass electro-oxidation was performed at room temperature using an electrochemical workstation (BioLogic EC-Lab).

[0052] Example 8 The solution after the electrocatalytic oxidative degradation reaction of plastics in Example 7 was sampled for product analysis.

[0053] Nuclear magnetic resonance (NMR) analysis revealed that ethylene glycol in the PET hydrolysate underwent an anodic oxidation reaction, selectively breaking C-C bonds to form formate. Further addition of formic acid to the electrolyte and filtration yielded high-purity, high-value-added terephthalic acid. Further concentration and crystallization of the filtrate yielded high-value-added potassium diformate (KDF). The purity of the product was confirmed by X-ray powder diffraction and single-crystal diffraction. The study found that different catalysts yielded varying results in the electrocatalytic oxidative degradation of plastics, compared to the etched Pd / CuO. x CuO / C and commercial Pd / C (20% Pt content) catalysts, Pd / CuO x Bimetallic catalysts exhibit the highest reactivity. It should be noted that the room temperature mentioned in the above embodiments refers to a temperature of 15-25°C; in addition, the atomic ratio of noble metals in the catalyst is obtained by ICP-OES testing and calculation.

[0054] Example 9 Pt / TiO2 synthesis method: Weigh 28 mg C 10 H 14 O4Pt and 1.62 mg TiO2 (P25), C 10 H 14Pt and TiO2 were mixed and then combined with 14 mL of benzyl alcohol (C6H5CH2OH) in a pressure-resistant flask. After stirring at room temperature for 5 minutes, the mixture was heated to 180°C in an oil bath and stirred vigorously for 3 hours, with CO continuously bubbled into the pressure-resistant flask during the heating process. After heating, the mixture was cooled to room temperature, centrifuged to obtain a black solid, which was repeatedly washed, centrifuged, and dried to obtain Pt / TiO2.

[0055] Pt / C synthesis method: Weigh 28 mg of C 10 H 14 O4Pt and 1.62 mg carbon black, C 10 H 14 O4Pt was mixed with carbon black and then mixed with 14 mL of benzyl alcohol (C6H5CH2OH) in a pressure-resistant flask. After stirring at room temperature for 5 minutes, the mixture was heated to 180°C in an oil bath and stirred vigorously for 3 hours, during which CO was continuously bubbled into the pressure-resistant flask. After heating, the mixture was cooled to room temperature, and the reaction solution was centrifuged to obtain a black solid. This solid was then centrifuged repeatedly, washed, and dried to obtain Pt / C.

[0056] Example 10 Electrocatalytic oxidation of HMF was carried out using the catalyst prepared in Example 9 and commercial TiO2 (P25).

[0057] Pt / TiO2 was used as a catalyst: a 1 mol / L KOH solution was prepared as the cathode electrolyte (20 mL), and a 1 mol / L KOH + 50 mmol / L HMF solution was prepared as the anolyte (20 mL). These solutions were then transferred to a three-electrode system, and carbon paper (0.5 cm²) was used for electrode preparation. 2 A platinum foil electrode was used as the working electrode, a mercury / mercury oxide electrode (Hg / HgO) as the counter electrode, and a mercury / mercury oxide electrode as the reference electrode. 500 μL of catalyst ink (4 mg / mL, 0.5% Nafion) was dropped onto the working electrode surface. Both biomass conversion and plastic electrooxidation were performed at room temperature using an electrochemical workstation (BioLogic EC-Lab). The reaction results are shown below. Figure 6 As shown.

[0058] Pt / C as catalyst: The operation steps are the same as those for Pt / TiO2 as catalyst, except that Pt / TiO2 is replaced with Pt / C. The reaction results are as follows. Figure 6 As shown.

[0059] TiO2 as a catalyst: The operation steps are the same as those for Pt / TiO2 as a catalyst, except that Pt / TiO2 is replaced with TiO2, and the reaction results are as follows. Figure 6 As shown.

[0060] from Figure 6 As can be seen, TiO2 did not exhibit any reactivity in the electrocatalytic oxidation of HMF, while the peak current density of the Pt / TiO2 bimetallic catalyst reached 34 mA / cm². 2 It is a Pt / C catalyst (22 mA / cm). 2 The value is 1.6 times that of the noble metal / transition metal oxide NM / TMO, indicating that the ratio is 1.6 times higher. x The interface effectively promotes efficient electrocatalytic oxidation of biomass conversion and plastic degradation at room temperature.

[0061] Example 11 The product distribution was analyzed by sampling the electrolyte after the HMF electrocatalytic oxidation reaction of the catalyst in Application Example 10 at different voltages (0.6 V, 0.8 V, 1.0 V).

[0062] The product detection conditions were as follows: 1 mol / L KOH solution was prepared as the cathodic electrolyte (15 mL), and 1 mol / L KOH + 6 mmol / L HMF solution was prepared as the anodic electrolyte (15 mL). Reactions were conducted at different voltages (0.6 V, 0.8 V, 1.0 V) and at different coulombic values ​​(0 C, 17.4 C, 19.3 C, 29.95 C), with 75 μL samples taken and diluted to 1.5 mL with 1.425 mL of 5 mM ammonium formate aqueous solution (70%) + methanol (30%). The product was quantitatively detected using high-performance liquid chromatography (HPLC). After the column pressure stabilized, detection was performed using a full-wavelength UV detector with a diode array. The wavelength with the strongest product response and highest resolution (265 nm) was selected for spectral collection and quantification. Each injection volume was 10 μL. Product data were converted to standard values ​​and statistically analyzed.

[0063] The product test results of Pt / TiO2 and Pt / C catalysts under different voltages are as follows: Figure 7 .

[0064] from Figure 7 As can be seen, the products of the reaction of each catalyst at different voltages (0.6 V, 0.8 V, 1.0 V) are quite different. Among them, Pt / TiO2 has a selectivity for FDCA close to 100% at 0.8 V, which is significantly improved compared to Pt / C (62.7% FDCA selectivity).

[0065] Example 12 Cyclic stability testing and product detection were performed on Pt / TiO2.

[0066] The stability test and product detection conditions were as follows: 1 mol / L KOH solution was prepared as the cathode electrolyte (15 mL), and 1 mol / L KOH + 6 mmol / L HMF solution was prepared as the anolyte (15 mL). These solutions were then transferred to a three-electrode system (H-type electrolytic cell) and carbon paper (2 cm²) was used. 2 A platinum foil electrode was used as the working electrode, a mercury / mercury oxide electrode (Hg / HgO) as the reference electrode, and 2 mL of catalyst ink (10 mg / mL, 0.5% Nafion) was dropped onto the working electrode surface. Ten chronoamperometry tests were performed at room temperature (0.8 V vs. RHE) using an electrochemical workstation (BioLogic EC-Lab), and 75 μL samples were collected at different coulombic values ​​(0 C, 17.4 C, 19.3 C, 29.95 C). The samples were diluted to 1.5 mL with 1.425 mL of 5 mM ammonium formate aqueous solution (70%) + methanol (30%). Quantitative analysis of the product was performed using high-performance liquid chromatography (HPLC). After the column pressure stabilized, detection was performed using a full-wavelength UV detector with a diode array. The wavelength with the strongest product response and highest resolution (265 nm) was selected for spectral collection and quantification. Each injection volume was 10 μL. Product data were converted to standard values ​​and statistically analyzed.

[0067] from Figure 8 As can be seen, the products of the Pt / TiO2 catalyst undergoing 10 consecutive cycles at a voltage of 0.8 V show little difference, and the selectivity for FDCA is very high, close to 100%, indicating that the Pt / TiO2 catalyst has good stability and strong repeatability.

[0068] In summary, this invention overcomes the shortcomings of the prior art and provides a method for constructing NM / TMO. x The / C binary metal interface method exhibits fast reaction rates, high selectivity for corresponding multi-electron products, good stability, and strong reproducibility in electrocatalytic oxidation of biomass conversion and plastic degradation at low potentials (<1.0 V).

[0069] The above embodiments have provided a detailed description of the present invention, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent variations and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. An electrocatalyst for biomass conversion, characterized in that, This catalyst uses carbon-based materials as catalyst supports and is a supported catalyst NM / TMO with a noble metal / transition metal oxide interface structure prepared by loading metals and metal oxides. x / C; where NM is the noble metal Pt, TM is the transition metal Cu, and the loading of NM is 0.5wt%-35wt%, and the loading of TM is 1wt%-30wt%; The preparation method of the electrocatalyst for biomass conversion includes the following steps: (1) Take a transition metal salt and add it to ultrapure water, stir, and then add the catalyst support and stir; (2) Add a reducing agent to the solution obtained in step (1) and perform mechanical stirring reaction; (3) The sample TM / C with transition metal loaded on a carrier was obtained by filtration, washing, centrifugation and drying; (4) Take the sample TM / C obtained in step (3) and disperse it in the noble metal precursor solution, and stir continuously. Then, filter, wash, centrifuge and dry to obtain the catalyst NM / TM / C. (5) Take the NM / TM / C obtained in step (4) and put it into a muffle furnace. Calcinate it in air. After calcination, cool it to room temperature to obtain NM / TMO. x / C; The roasting temperature in the muffle furnace is 100~200°C, and the roasting time is 2~3 h; The electrocatalyst is used for the electrocatalytic oxidation of 5-hydroxymethylfurfural at a low potential of less than 1.0 V.

2. The method for preparing an electrocatalyst for biomass conversion according to claim 1, characterized in that, In step (1), the carbon-based material is activated carbon, carbon black, graphene and its derivatives, carbon quantum dots, carbon nanofibers or carbon nanotubes.

3. The method for preparing an electrocatalyst for biomass conversion according to claim 1, characterized in that, In step (2), the reducing agent is sodium borohydride solution, potassium borohydride solution or hydrazine hydrate.

4. The method for preparing an electrocatalyst for biomass conversion according to claim 1, characterized in that, In step (4), the noble metal precursor solution is a Pt-containing solution. 4+ An aqueous solution.

5. The method for preparing an electrocatalyst for biomass conversion according to claim 1, characterized in that, In steps (3) and (4), the water used for washing needs to be deoxygenated by argon gas beforehand.

6. The application of the electrocatalyst according to claim 1, characterized in that, Used for the electrocatalytic oxidation of 5-hydroxymethylfurfural.

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